Current-control apparatus



May 28, 1935. c. P. WEST CURRENT CONTROL APPARATUS Filed Nov. 26, 1932 2Sheets-Sheet l INVENTOR Charles P West.

' WITNESSES:

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Patented May 28, 1935 UNITED STATES PATENT OFFICE 2,003,024CURRENT-CONTROL APPARATUS Pennsylvania Application November 25, 1932,Serial No. 644,285

11 Claims.

sity of elaborate flood-lighting installations to provide some means forproducing a record, one for each circuit, which can be laid out inadvance and then utilized in conjunction with the control apparatus tocontrol the light intensity in accordance with a predetermined program.

An object of my invention, generally stated, is

to provide apparatus for controlling the current in a plurality ofelectrical circuits which shall be simple and efiicient in operation andwhich may be readily and economically manufactured and installed.

- A more specific object of my invention is to provide for controllingthe current in a plurality of electric circuits in accordance with apredetermined program,

A further-object of my invention is to provide a current-controllingsystem in which the program of control may be readily changed asdesired.

Other objects of my invention will be described fully hereinafter orwill be apparent to those skilled in the art.

As one embodiment of my invention, an alternating-currentlightingcircuit is controlled by means of a magnetic amplifier such a a reactorhaving a direct-current control wi ding. The control winding of thereactor is energized through an amplifying circuit comprising aplurality of thermionic tubes. The grid-biasing potential applied to thecontrol tube of the amplifying circuit is regulated by a potentiometerover which a roll of paper, or other non-conduct ing material, having aconducting track disposed thereon is passed. The potential impressed onthe conducting track by the potentiometer is determined by the portionof the potentiometer with which the track is in contact which, in turn,is determined by the location of. the track on the roll as it is passedover the potentiometer. The track may be so laid out on the roll thatthe biasing potential applied to the tube unit will be varied asdesired, thereby providing a flexible and easily constructed means ofcontrolling the current in a lighting or any other electrical circuit inaccordance with a predetermined program.

For a fuller understanding of the nature and scope of my invention,reference may be had to the following detailed description, taken inconjunction with the accompanying drawings, in which:

Figure 1 is a view, in elevation, of one unit of an embodiment of myinvention;

Fig. 2 is a view, partially in elevation and partially in section, takenalong the line 11-11 of Fig. 1;

Fig. 3 is a schematic diagram, illustrating the connections of alighting control circuit which may be controlled by my invention;

Fig. 4 is a top plan view of a modification of my invention, and

Fig. 5 is a view, in elevation of the embodiment of the invention shownin Fig. 4.

Referring to the drawings, and particularly to Figs. 1 and 2, which showone of a plurality of units which may be utilized for controlling aplurality of electrical circuits, a potentiometer I0 is wound upon aroller which is mounted upon a supporting panel ll. As shown, contactfingers l2 are disposed to engage contact rings i3 on-the ends of theroller thereby providing means of connecting the terminals of thepotentiometer to a battery or other suitable source of direct-currentenergy.

In the embodiment'of the invention illustrated in Figs. 1 and 2 aconducting track l4, composed of copper braid, is secured to a celluloidribbon I5 which may be wound from a spool l6 onto a similar spool l'l.It will be understood that the ribbon l5 may be composed of paper orother suitable material, also that thetrack [4 may be drawn on theribbon with a suitable conducting material, such as india ink or thelike. y

The spool I1 and the film or ribbon 5 are driven by a mechanical drivesimilar to that utilized on motion picture machines and comprising amotor l8 which drives a sprocket wheel 19 through a shaft 20 and a wormgear 2|. The

spool H is driven by a spring'belt 22, thereby prosired, instead ofproviding the pick-up roller 24,

the end of the conducting track l4 may be connected to the shaft of thespool l1 and the potential taken from the shaft by means of abrush,

similar to the brush 25, which engages the shaft on which the spool H ismounted.

It is evident that as the film l5 and the conducting track |4 pass overthe potentiometer III the potential impressed on the conducting trackwill vary as its location on the film varies. That is, if the track I4is so located on the film that it is travelling under one end ofthepotentiometer a low voltage will be impressed on the track and if thetrack is travelling under the other end of the potentiometer, a highvoltage will be impressed on the track. Similarly, when the track makescontact with intermediate points on the potentiometer, a correspondingvoltage is impressed thereon.

As previously stated, the pick-up roller 24 is disposed to engage thetrack l4 shortly after, it leaves the potentiometer l0 so that thevoltage on the pick-up. roller is determined by the position of thetrack |4 under the potentiometer Ill. By means of the brush 25, whichengages the roller 24, and a conductor 26 the varying potential of thetrack l4 may be impressed on a thermionic-tube amplifying unit and.thereby utilized to control the current in an electric circuit such as atheatre lighting circuit or an ornamental flood-lighting circuit.

It is apparent that the track l4 may be previously so laid out on thefilm |5 that the desired intensity of illumination will be secured atany time during the progress of the film under the potentiometer, alsothat the location of the track on the film may be easily altered inorder to vary the lighting effects secured. In this manner a flexibleand easily constructed means for laying out a program for controllingthe current in an electric circuit is provided. If it is desired tocontrol a plurality of circuits, additional units similar to the oneshown may be provided, a roll of film having a conducting track beingprovided for each circuit. The rolls may be mounted on additional panelsand driven by the shaft 20 and worm gears in a manner similar to thatshown. Since all of the rolls are driven by a common shaft, they operateat the same speed, thereby keeping the programs of the various circuitsin synchronism.

A thermionic tube amplifying circuit of the type illustrated in Fig. 3,and which is fully described in Patent Nol 1,966,222, issued July 10,1934, to R. D. Ross, and assigned to the Westinghouse Electric andManufacturing Company may be utilized in conjunction with the apparatusherein described to control the current in a lighting circuit. However,it will be understood that amplifying circuits of various other types,well known in the art, may be readily utilized in conjunction with myinvention.

Referring to Fig. 3, a lighting circuit 30 is illustrated as havinglamps 3| supplied with al- .ternating current through conductors 32which may be energized from any suitable source of alternating current.The current flowing through the lamps 3| is controlled by a three-leggedreactor 33 in a manner described in the copending application of R. D.Ross. The reactor 33 is provided with alternating-current windings 34and 35 and a direct-current control winding 36. The normal inductance ofthe windings 34 and 35 is such that the lamps 3| will not be lighted,however, by energizing the control winding 36 with direct current theiron core of the reactor is saturated to a degree depending upon thecurrent flowing in the winding 36, thereby reducing the impedance of thewindings 34 and 35 and permitting the lamps 3| to be lighted. In thismanner the intensity of the illumination supplied by the lamps 3| may becontrolled by varying the amount of direct current flowing in thecontrol winding 36.

As shown, the control winding 35 may be energized by means of adirect-current generator 31 or other suitable source of power throughthe plate circuits of two tubes 38 and39 which are connected inparallel-circuit relation. The plate current of these tubes may beregulated by means of a control tube 4| in cooperation with adirectcurr'ent generator 42 or other suitable source and resistors 43and 44, as described in the aforementioned copending application of R.D. Ross. A varying grid-biasing potential is impressed on the grid ofthe tube 4| by means of the potentiometer I0 and the conducting trackhereinbefore described. In this manner the current fiowing in thelighting circuit 30, and hence the intensity of illumination supplied bythe lamps 3|, may be controlled in accordance with a predeterminedprogram by merely running the film l5 through the control apparatus. Aspreviously stated, the intensity of illumination secured at any timeduring the program may be varied by changing the location of the track Mon the film l5, and additional units may be provided for controlling aplurality of -circuits.

In the embodiment of the invention illustrated in Figs. 4 and 5 aplurality of conducting tracks M are disposed on a revolving disc 50instead of the film I5. The disc 50 is driven by a motor |8 through agear reduction 5|. The disc may be composed of Micarta, or any othersuitable insulating material and the tracks I4 may be-laid out with aconducting ink or they may consist of copper braid or the like securedto the disc in any suitable manner.

As shown, two continuous tracks l4 are laid out on the top side of thedisc 50 and two on the bottom side, thereby providing a means ofcontrolling four electric circuits similar to the lighting circuitillustrated in Fig. 3.

Potentiometer windings Ill are wound upon rollers which are mountedabove and below the revolving disc 50 in a manner to permit each of theconducting tracks M to make contact with one of the potentiometers Hi.The tracks |4 may be so laid out on the disc 50 that a varying voltagewill be impressed on them as the disc revolves, thereby controlling theintensity of the illumination supplied by each of the lighting circuitsin accordance with a predetermined program.

Since the tracks are continuous the program for 'each circuit isrepeated with each revolution of the disc 50. Pick-up rollers 24 aremounted above and below the disc 5|! in a manner similar to thepotentiometers Hi to engage the tracks M in order that the voltageimpressed on each of the tracks may be transmitted to the controlcircuits. Each of the pick-up rollers is provided with a collectingbrush 25 whichmay be connected to.

the grid of a thermionic tube, thereby providing a means of controllingthe current in an electric circuit, as previously described.

It will be understood that provision may be made for controlling anydesired number of circuits by increasing the number of trackson eachdisc and also by providing additional units similar to the oneillustrated.

The program of control may be varied by changing the lay-out of thetracks M on the disc and entirely new programs may be provided by fplacing new discs, having different track layouts, in. the controlapparatus. The frames which support the potentiometer and the pickuprollers are hinged at 52 in order that the disc 50 may be readilyremoved and a different one inserted in its place.

As previously stated, the invention herein described is not'limited tothe control of lighting systems, but it may be readily utilized invarious other electricalcontrol systems, as, for example,load-dispatching systems, wherein it is desired to regulate the load ona particular circuit or system, in accordance with a predeterminedschedule.

It may also be utilized to control the operation of electricallycontrolled valves, conveyors and other apparatus, the operation of whichmay be controlled in accordance with a predetermined program.

Since numerous changes may be made in the above-described construction,and different embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

lQIn apparatus for controlling an electrical condition of a circuit, incombination, a rotatable potentiometer winding, means for impressing asubstantially constant potential on the potentiometer winding,conducting means disposed on a carrier to engage varying portions of thepotentiometer winding to receive a potential which' varies in accordancewith the position of the conducting means on the carrier, and means forimpressing said varying potential on an electric circuit to control anelectrical condition thereof.

2. In apparatus for controlling an electrical condition of a circuit, incombination, a potentiomemr winding, means forimpressing a substantiallyconstant potential on the potentiometer winding, a conducting trackdisposed to engage the potentiometer winding at predetermined points toreceive a potential which varies in accordance with a predeterminedprogram, and means for impressing said varying potential on an electriccircuit to control an electrical condition thereof.

3. In apparatus for controlling an electrical condition of a circuit, incombination, a rotatable potentiometer winding, means for impressing asubstantially constant potential on the potentiometer winding, aflexible electrical conductor, means for moving the flexible electricalconductor across the potentiometer winding to engage it at predeterminedpoints to receive a potential'which varies in accordance with apredetermined program, and means for impressing said varying potentialon an electric circuit to control an electrical condition thereof.

4. In apparatus for controlling an electrical condition of a circuit, incombination, a potentiometer winding, means for impressing asubstantially constant potential on the potentiometer winding, a trackcomposed of an electrical conducting material, a non-conducting carrierfor supporting the track, means for moving the carrier and the trackacross the potentiometer winding to'engage it at predetermined points toreceive a potential which varies in accordance with a predeterminedprogram, and means, for impressing said varying potential on an electriccircuit to control an electrical condition thereof.

5. In apparatus for controlling an electrical condition of a circuit, incombination, a poten- I tiometer winding, means for impressing a sub--stantially constant potential on the potentiometer winding, a conductingtrack disposed on a flexible non-conducting carrier in a predetermined Ilayout, means for moving the carrier across the) potentiometer windingto cause the track to engage the potentiometer winding at predeterminedpoints in accordance with the layout of said track to receive a varyingpotential from said poten tiometer, and means for impressing saidvarying potential on an electric circuit to control an electricalcondition thereof.

6. In apparatus for controlling an electrical condition of a circuit, incombination, a potentiometer winding, means for impressing asubstantially constant potential on the potentiometer winding, aflexible con-ducting track disposed on a non-conducting carrier in apredetermined layout, means for moving the carrier across thepotentiometer to cause the track to engage the potentiometer atpredetermined points in accordance with the layout of said track toreceive a varying potential from said potentiometer, andconducting'means disposed to engage said track to impress said varyingpotential on an electric circuit to control an electrical conditionthereof.

'7. In apparatus for controlling an electrical condition of a circuit,in combination, a potentiometer wound upon a rotatable spool, means forimpressing a potential on the potentiometer winding, a flexibleconductor disposed upon a ribbon of non-conducting material in apredetermined layout, means for drawing the ribbon across thepotentiometer to cause the conductor to engage the potentiometer atpredetermined points in accordance with the layout of the conductor toreceive a varying potential from said potentiometer, and conductingmeans disposed to engage the flexible conductor to impress said varyingpotential on an electric circuit to control an electrical conditionthereof.

8. In apparatus for controlling an electrical.

means for impressing said potential on an electric circuit to control anelectrical condition thereof.

9. In apparatus for controlling an electrical condition of a circuit, incombination, a potentiometer win-ding, means for impressing a potentialon the potentiometer winding, a conductor disposedupon a disc ofnon-conducting material in a predetermined layout, means for revolvingthe disc to cause the conductor to engage the potentiometer atpredetermined points in accordance with the layout of the conductor toreceive a varying potential from the potentiometer, a pick-up rollerdisposed to engage the conductor to receive the varying potential, andmeans for impressing said potential on an electric circuit to control anelectrical condition thereof.

10. In apparatus for controlling an electrical condition of a pluralityof circuits, in combination, a plurality of potentiometer windings,means for impressing a potential on the potentiometer windings, aplurality of conductors disposed upon tion, a plurality ofpotenti'ometers wound uponrotatable spools, means for impressing apotential on the potentiometer windings, a plurality of conductorsdisposed upon the top side of a disc'of non-conducting material inpredetermined layouts, a plurality of similar conductors disposed uponthe bottom side of said disc, means for revolving the disc to cause theconductors to engage the potentiometers at predetermined points inaccordance with the layout of the conductors to receive varyingpotentials from the potentiometers, a plurality of pick-up rollersdisposed to engage the conductors to receive the varying potentials, andmeans for impressing said potentials on electric circuits to control anelectrical condition thereof.

CHARLES P. WEST.

